NEAA Digital

Curriculum vitae

Darryl Kay

Senior Frontend Engineer

React · Next.js · React Native · Expo · TypeScript

Senior Software Engineer specialising in React, Next.js, React Native and TypeScript, building accessible, user-focused web applications, mobile apps and internal business tools.

Hands-on delivery across start-ups, scale-ups and enterprise organisations, from greenfield development to modernising existing platforms. Experience spans reusable design systems, API integration and technical leadership, working directly with product, design, Finance and executive teams.

Experience

  1. B-Flexion

    Contract

    Senior Software Engineer

    Private investment and asset management business.

    • Implemented a reusable design system in Storybook, documenting components and interactions for developers, designers, business analysts and product managers to support consistent interfaces and future development.
    • Develop a Next.js forecasting platform with Finance and executive stakeholders, providing visibility into projected revenue and the company's expected future financial position.
    • Redesign the existing React/Vite AI platform and use supplied Figma designs as a reference when developing accessible interfaces and reusable components.
    • Use Zustand for state management and Playwright for end-to-end testing.

    Tech used:

    • React
    • Next.js
    • Vite
    • Zustand
    • Playwright
    • Storybook
    • Figma

  2. Trotter Concierge

    Contract

    Full-Stack / React Native Engineer

    Travel-technology scale-up within the B-Flexion group.

    • Developed the React Native/Expo mobile app, coordinated App Store releases and contributed to the customer-facing website.
    • Built and supported Next.js internal tools for customer communications, requests and payment workflows.
    • Implemented and debugged Node.js/Express APIs, made targeted database schema changes using Prisma and used Redux for application state management.
    • Supported Customer.io, AppsFlyer and RevenueCat integrations; investigated application errors using Sentry and maintained and debugged AWS cloud functions.

    Tech used:

    • React Native
    • Expo
    • Next.js
    • TypeScript
    • Redux
    • Node.js
    • Express
    • Prisma
    • AWS
    • Sentry
    • Customer.io
    • AppsFlyer
    • RevenueCat

  3. On the Beach

    Permanent

    Senior React Native Engineer

    Online travel and holiday-booking business.

    • Restructured an existing React Native codebase into a modular, maintainable architecture while helping lead technical direction.
    • Partnered with product stakeholders to define and deliver features; mentored engineers and improved development practices.
    • Used Redux Toolkit and RTK Query for state management and data fetching, Jest for automated tests and Maestro for end-to-end testing.

    Tech used:

    • React Native
    • TypeScript
    • Redux Toolkit
    • RTK Query
    • React Navigation
    • Jest
    • Maestro
    • MMKV

  4. Pets at Home

    Permanent

    Senior / Lead React Native Engineer

    UK pet retailer and consumer-services business.

    • Joined as the first React Native engineer on a greenfield app and progressed to Lead Developer, leading 15 engineers across multiple squads.
    • Established mobile architecture, engineering standards and release processes, contributing to the application launch in 2024.
    • Collaborated with product, design, QA and backend teams; mentored developers, participated in hiring and supported app releases and Azure DevOps CI/CD pipelines.
    • Used Jest and React Native Testing Library for automated tests, with Playwright running against the Appetize-hosted app for browser-based end-to-end testing.

    Tech used:

    • React Native
    • TypeScript
    • Redux Toolkit
    • React Navigation
    • Jest
    • React Native Testing Library
    • Playwright
    • Appetize
    • Storybook
    • Azure DevOps

  5. The Modern Milkman

    Permanent

    React / React Native Developer

    Sustainable grocery delivery and subscription-commerce business.

    • Established foundations for greenfield React and React Native projects before moving to an existing logistics-focused mobile product.
    • Implemented interfaces with designers, integrated REST APIs with backend engineers and developed automated tests.

    Tech used:

    • React
    • React Native
    • TypeScript
    • Redux
    • Redux Saga
    • Jest
    • React Native Testing Library

  6. Connexas

    Permanent

    Software Developer

    Provider of SaaS business software.

    • Developed Angular/TypeScript interfaces, resolved defects and integrated REST APIs, with targeted C# backend integration changes.

    Tech used:

    • Angular
    • TypeScript
    • HTML
    • CSS
    • C#

  7. PI Brand Solutions / J'nik's Events Catering

    Freelance

    Freelance Web Developer

    Separate website engagements for a marketing agency and an events catering business.

    • Gathered business requirements, designed and built React websites and maintained reusable frontend components.

    Tech used:

    • React
    • JavaScript
    • HTML
    • CSS

Technical skills

  • Frontend & mobile

    • React
    • Next.js
    • React Native
    • Expo
    • TypeScript
    • JavaScript
    • Vite
    • Angular

  • State management

    • Zustand
    • Redux
    • Redux Toolkit
    • RTK Query
    • Redux Saga

  • Backend & APIs

    • Node.js
    • Express
    • REST APIs
    • Prisma
    • AWS cloud functions

  • Testing & delivery

    • Playwright
    • Maestro
    • Jest
    • React Native Testing Library
    • Appetize
    • GitHub Actions
    • Azure DevOps

  • Architecture & practices

    • Design systems
    • Storybook
    • Figma collaboration
    • Accessible UI
    • Greenfield development
    • Brownfield modernisation
    • Technical leadership